Back to this thread....
Some charts to share:
I always start with 4" nearfield measurements, in this case the IB sub show how flat it is from the get go to ULF, the 12" box sub.....well it shows what looks like a HPF at 27hz?
I had both of these gain calibrated @ 75db seat #2 - about 11 ft away, the box sub it was put away from the corner to lessen the effect of corner on it.
I was kinda surprised how much "hotter" the box sub was at nearfield than the IB sub, which of course means the IB sub just carries itself so much better thru the room.
Here is overlay of the IB sub seats 1-4 with overlay of the IB sub seats 5-8, both these are pretty close to what I measured 1 year ago so I feel my hardware set-up and cal file is correct
Now, after I took all these measurements, and extracted charts, I realized that I did the 75db calibration yesterday, box sub via its front gain knob, while the IB sub the MV gain, and then it was home movie time for the family so I shutdown the set-up.
However, upon waking up this morning and firing up everything, I think I forgot to re-set the AVR to -27.5db, it goes to -40db at shut-down...duh on me
(the box sub of course gain is via the front knob)
I changed it during initial set-up back....or partly in....it was 5am.....
So I'll have to re-do a few to see if all my work this morning is good or needs re-doing.
anyway some observations:
I had the 12" box sub set-up like this; low pass 140hz, phase normal, pretty basic settings
It was actually facing the corner, along the 34" triangle face, to simulate same driver plane as outward corner box would, hopefully this was ok?
A "few" measurements later....and extracting charts....(for people who have not done this, this is the part that needs attention, putting good notes into each measurement group so later don't get confused)
I did each seat position like this, mic same position of course:
-12" box sub separately
-IB sub separately
-both subs running
Seat#1; you can never use the avg to join 2 subs measurements, , my early guess said should be able to but it never matched the combo sub measurement.
Seat#2 & Seat#3
From those 4 charts, hard to see;
-I find it hard to grasp why the box sub pulls down the IB sub consistently in it's roll-of below 27hz area......I'd love to have a real capable sub to test this out, one that goes at least 15hz before roll off.
-Next round of charts I'll not show the "avg plot", that confuses
Next post: seats 5-8